Option B - Thermodynamics Year 13 SL Physics

Thermodynamics System – Environment of activity Surroundings – Factors impacting the system Boundary (wall) – System barriers

Work on a System Work done on a system or energy transferred to the system because of temperature differences result in the internal energy of that system increasing No change in state – Increase in Kinetic Energy Change in State – Increase in potential energy

Internal Energy Total Internal Energy of a System = – Total Potential Energy + Random Kinetic Energy of all particles

Ideal Gas Internal Energy is all kinetic

0 th Law of Thermodynamics

1 st Law of Thermodynamics Changes to Internal Energy – Doing work on the system Allowing the system to do work on the surroundings – Transferring energy to or from the system as a result of a difference in temperature

Q = ΔU + W

Types of Work Done Isobaric Changes – Constant Pressure Isothermal Changes – Constant Temperature Adiabatic Changes – Constant Energy Isovolumetric Changes – Constant Volume

Isobaric Changes Pressure is constant Q = ΔU + pΔV W is positive = expands W is negative = compressed

Isobaric Changes

Isothermal Changes Temperature is constant – So internal energy of the system remains constant Q = W – Where W = pΔV

Isothermal Change

Adiabatic Changes Constant Energy – No energy is transferred Usually contains a well insulated barrier between the system and surroundings

Isovolumetric Changes Constant volume – So no work done Q = ΔU

2 nd Law of Thermodynamics It is impossible to transfer energy from a body at a lower temperature to one at higher temperature without doing work on the system It is impossible to extract energy from a hot reservoir and transfer this entirely into work. Law of Entropy

Entropy

We will do some examples and practice problems on Friday. But please learn these terms – That means you will need to study them Hubert